Case Archetypes: Legacy Modernization
This page covers the legacy modernization instantiation. The continuous SDLC archetypes are on Case Archetypes: Continuous SDLC.
The case studies below illustrate the breadth of legacy stacks the methodology has modernized. The list is representative rather than exhaustive. The five-stage modernization lifecycle and the per-language adapters in the modernization agent fleet extend across legacy stacks beyond those shown here.
Delivery duration on any specific engagement depends on the organization’s path-to-production process and the modules selected for migration. Effort and time outcomes are reported below; cost outcomes are framed engagement by engagement.
The Case Studies
| Case study | Industry | Modernization type | Delivery |
|---|---|---|---|
| Framework Modernization: SaaS / Healthcare | SaaS / Healthcare | Struts / Hibernate / EJB → Java Spring MVC | ~3.2M LOC · ~5 months |
| Mainframe Modernization: Insurance | Insurance | COBOL on AS400 → .NET 8 microservices, React | 600K LOC |
| Legacy Modernization: Edu Tech | Education Technology | Delphi → cloud-native .NET 8 | ~3M LOC · ~8 months |
| Monolith Re-Architecture: Logistics | Logistics | VB.NET monolith → modular .NET Core, React | 300K LOC · ~5 months |
| Version and Platform Upgrade: Inventory | Inventory and Warehouse | Java 8 → Java 21 | 2.1M LOC · ~3.5 months |
| Legacy Modernization (SOA): Financial Services | Financial Services | ASP.NET Web Forms → .NET Core 8 SOA, Angular 19 | 300K LOC |
| Monolith to Microservices: Fuel and Billing | Fuel and Billing | ASP.NET monolith → .NET 10 microservices, React 19 | 825K LOC |
Framework Modernization: SaaS / Healthcare
Client. Cloud-based Revenue Cycle Management (RCM) tool used by a life-sciences company to automate complex pricing, contracting, and rebate processes.
| Element | Detail |
|---|---|
| Project highlights | ~3.2M LOC of Struts / Hibernate / EJB migrated to Java Spring MVC. Multi-staged migration with automated unit tests. |
| Impact delivered | No impact on user experience during cutover. Eliminated security vulnerabilities. Major reduction in manual effort across the engagement. |
| Delivery | ~5 months. |
Mainframe Modernization: Insurance
Client. Core group insurance platform powering policy lifecycle operations for employers and employees. Modernization was essential to business continuity and scale.
| Element | Detail |
|---|---|
| Project highlights | 600K LOC COBOL on AS400 migrated to .NET 8 microservices with a React frontend. |
| Impact delivered | Removed mainframe dependency and scarce-skill exposure. High-fidelity automated transformation. Parallel migration streams enabled across the estate. |
Legacy Modernization: Edu Tech
Client. Mission-critical education platform supporting payments, communication, and institutional workflows. 80%+ market share in Europe.
| Element | Detail |
|---|---|
| Project highlights | 3M LOC Delphi migrated to cloud-native .NET 8. Desktop application moved to a web platform. |
| Impact delivered | ~60% effort reduction versus manual. Scalable modern user experience. Faster feature delivery. Cloud-ready foundation for growth. |
| Delivery | ~8 months. |
Monolith Re-Architecture: Logistics
Client. Core logistics platform enabling operational execution, scalability, and faster business response.
| Element | Detail |
|---|---|
| Project highlights | 300K LOC VB.NET monolith migrated to modular .NET Core. React frontend with a refreshed user experience. |
| Impact delivered | Higher modularity for future enhancements. Improved maintainability and developer onboarding. Faster enhancement cycles. |
| Delivery | ~5 months. |
Version and Platform Upgrade: Inventory and Warehouse
Client. Core inventory and warehouse platform enabling synchronization, operational visibility, and scalable fulfillment performance.
| Element | Detail |
|---|---|
| Project highlights | 2.1M LOC Java 8 to Java 21 in approximately 3.5 months. Automated detection and replacement of deprecated APIs. |
| Impact delivered | Doubled inventory synchronization throughput. Improved overall system performance. ~3× faster than manual migration. |
Legacy Modernization (SOA): Financial Services
Client. Critical lending approval platform supporting financial decisioning, compliance-sensitive workflows, and faster business agility.
| Element | Detail |
|---|---|
| Project highlights | 300K LOC ASP.NET Web Forms migrated to .NET Core 8 SOA. Angular 19 frontend with a REST API bridge layer. |
| Impact delivered | Business agility and faster enhancement cycles. AI-generated documentation for the migrated application. Preserved undocumented data-access logic from the legacy system. |
Monolith to Microservices: Fuel and Billing
Client. Configurable fuel and billing platform powering transaction processing, lending workflows, and customer-facing operational scale.
| Element | Detail |
|---|---|
| Project highlights | 825K LOC ASP.NET monolith migrated to .NET 10 microservices. React 19 frontend. AI-generated test suites. |
| Impact delivered | ~50% effort reduction versus manual. 20% faster transaction performance. 80%+ unit test coverage. 15% productivity lift from improved usability of the modernized application. |
Aggregate Track Record
| Indicator | Value |
|---|---|
| Legacy code modernized | 15M+ lines of code across ASP.Net, COBOL, Delphi, ASP Forms, VB.NET, and custom proprietary systems |
| Modernization programs delivered | 10+ at scale across large enterprises and regulated environments |
| Cross-industry footprint | Insurance and Finance, Healthcare and Life Sciences, Inventory and Logistics, Education Technology, Fuel and Billing |
| Continuous methodology innovation | 3+ years of field-tested evolution |
Indicative outcomes on a 1M LOC standalone codebase: up to 4× faster than manual modernization, up to 70% migration time reduction. Actual outcomes vary by engagement scope, target stack, and the modules selected for migration.
The companion to this page is Case Archetypes: Continuous SDLC, which covers two SDLC archetypes (brownfield enterprise modernization at 2M LOC and greenfield growing into complexity). ASIMOV is the platform that operationalizes the methodology for legacy modernization. Engagement Modes of Legacy Modernization covers the five engagement modes under which these case studies were delivered.